Within the domain of personal care, e.g. shaving and grooming, so-called “magic mirrors” form a relatively new concept. With such magic mirrors, for example, information is displayed behind or on a mirror surface to enhance the standard mirror experience. In a particular implementation the magic mirror may use a camera image to display a mirror-image on a screen overlaid with enhancements. However, it is difficult to replicate the mirror experience, e.g. depth, using a computer screen. In another implementation the magic mirror uses a display screen behind a two-way (semi-transparent) mirror. In this implementation, for example, the mirror transmits an illuminated display image from a back side of the mirror surface through the mirror surface to a front side thereof while reflecting a mirror image of the user at its front side.
To add further functionality to the mirror device, it is desired to provide the convenience of a touch input interface on the mirror surface. For this purpose existing mirror devices, for example, comprise touch technology, such as optical, resistive or conductive pads or pressure-sensitive pads. However, these touch technologies are relatively intrusive and not so easy to operate. Accordingly, it is preferred to use a capacitive touchscreen which is generally more responsive and used also in other display devices such as smartphones and tablets.
One method to create a conventional mirror surface is to use a metallic reflective layer. For example, a thin, deposited layer of aluminum or silver on a transparent substrate can be used as the mirroring plane. However, these metallic layers are also electrically conductive and therefore considered unsuitable in combination with capacitive sensors arranged behind the mirror surface. In particular, the presence of such a conductive layer may negate the function of the capacitive sensors.
The prior art U.S. Pat. No. 8,835,789 B2 describes apparatuses and methods for using a capacitive touch controller with a conductive surface. The known apparatus comprises a mirror having a reflective layer that is conductive and reflects light. A trench is formed in the reflective layer to define a touch area of the reflective layer that is isolated from the rest of the reflective layer. A conductive pickup is mounted on a back side of the mirror over the touch area and the conductive pickup is electrically connected to a capacitive touch controller, such that when a user touches the touch area on a front side of the mirror the touch controller responds to the touch. It is noted in the prior art that the known apparatus may suffer from cross-talk when multiple touch areas are intended. The prior art discloses to minimize the cross-talk between touch pads by increasing the trench widths. The prior art also discloses providing a source of backlight to make the trenches visible on a front side of the surface. However this may detract from a visual appeal of the mirror surface and only allow static touch controls.
Accordingly, there remains a desire to improve apparatuses and methods using a capacitive touch controller in combination with a conductive mirror surface.